RESUMEN
Ahead of Print article withdrawn by publisher.
RESUMEN
The mosquito Anopheles gambiae is an important vector for malaria, which is one of the most serious human parasitic diseases in the world, causing up to 2.7 million deaths yearly. To contribute to our understanding of A. gambiae and to the transmission of malaria, we have now cloned four evolutionarily related G protein-coupled receptors (GPCRs) from this mosquito and expressed them in Chinese hamster ovary cells. After screening of a library of thirty-three insect or other invertebrate neuropeptides and eight biogenic amines, we could identify (de-orphanize) three of these GPCRs as: an adipokinetic hormone (AKH) receptor (EC(50) for A. gambiae AKH, 3x10(-9)M), a corazonin receptor (EC(50) for A. gambiae corazonin, 4x10(-9)M), and a crustacean cardioactive peptide (CCAP) receptor (EC(50) for A. gambiae CCAP, 1x10(-9)M). The fourth GPCR remained an orphan, although its close evolutionary relationship to the A. gambiae and other insect AKH receptors suggested that it is a receptor for an AKH-like peptide. This is the first published report on evolutionarily related AKH, corazonin, and CCAP receptors in mosquitoes.
Asunto(s)
Anopheles/fisiología , Evolución Molecular , Insectos Vectores/fisiología , Neuropéptidos/farmacología , Receptores Acoplados a Proteínas G/clasificación , Receptores Acoplados a Proteínas G/efectos de los fármacos , Secuencia de Aminoácidos , Animales , Anopheles/genética , Células CHO , Clonación Molecular , Cricetinae , Cricetulus , Orden Génico , Hormonas de Insectos/farmacología , Proteínas de Insectos/farmacología , Insectos Vectores/genética , Malaria/transmisión , Datos de Secuencia Molecular , Oligopéptidos/farmacología , Filogenia , Ácido Pirrolidona Carboxílico/análogos & derivados , Ácido Pirrolidona Carboxílico/farmacología , Receptores Acoplados a Proteínas G/genética , Receptores de Neuropéptido/efectos de los fármacos , Receptores de Neuropéptido/genética , Receptores de Neuropéptido/fisiologíaRESUMEN
The insect myosuppressins (X1DVX2HX3FLRFamide) are neuropeptides that generally block insect muscle activities. We have used the genomic sequence information from the malaria mosquito Anopheles gambiae Genome Project to clone a G protein-coupled receptor that was closely related to the two previously cloned and characterized myosuppressin receptors from Drosophila [Proc. Natl. Acad. Sci. USA 100 (2003) 9808]. The mosquito receptor cDNA was expressed in Chinese hamster ovary cells and was found to be activated by low concentrations of Anopheles myosuppressin (TDVDHVFLRFamide; EC50, 1.6 x 10(-8)M). The receptor was not activated by a library of 35 other insect neuropeptides and monoamines, including neuropeptides that resembled myosuppressin in their C-terminal moiety, such as PDRNFLRFamide (Anopheles FMRFamide-3), other Anopheles FMRFamide peptides, or neuropeptide F-like peptides, showing that the receptor was quite selective for myosuppressin. These results also showed that the myosuppressin receptor needs a much larger portion than the C-terminal FLRFamide sequence for its activation. The insect myosuppressins are often grouped together with the insect FMRFamides under the name FaRPs (FMRFamide-related peptides). However, this is not justified anymore, because the insect myosuppressin receptor/ligand couple is both functionally and evolutionarily fully unrelated to the insect FMRFamide receptor/ligand couple. To our knowledge, this is the first report on the molecular identification of a mosquito neuropeptide receptor.